A 5G in-building relay service provides a millimeter-wave 5G service using broadband in 30˜300 GHz ultra high frequency.
The typical in-building repeater solves a dead spot in a building and improves the communication quality (VoC). Further, the typical in-building repeater establishes wireless coverage by installing a Radio Frequency (RF) cable and an antenna in the building. Hereinafter, the problem of the typical in-building repeater will be described, considering an optical distribution repeater as a most commonly used typical in-building repeater.
As the most commonly used typical in-building repeater, an optical distribution repeater 100 includes a Main Hub Unit (MHU) 101 and a Remote Optical Unit (ROU) 103, as shown in FIG. 1. The MHU 101 receives signal sources from radio stations and combines them and transmit the combined signals. The ROU 103 is installed in the building and receives a signal from the MUH 101 through an optical cable 102. The ROU 103 transmits a signal through an RF cable 104 in the building, and the transmitted signal is sent to a wireless terminal as a wireless RF signal through an antenna 105.
Because the typical LTE and 3G (WCDMA) services use the frequency range of 5 GHz or less, it is possible to transmit the corresponding RF signal and provide the service in the building through the RF cable 104. However, because a 5G service using a millimeter-wave uses the ultra-high frequency range, there are problems such as transmission distance restriction and performance degradation when a millimeter-wave is transmitted through the RF cable 104. Accordingly, it is impossible to provide a service using the typical in-building repeater 100.